Fsh

Fsh

Alternate Names

follicle-stimulating hormone

Definition

This is a blood test that measures the amount of follicle-stimulating hormone (FSH) produced by the pituitary gland.

Who is a candidate for the test?

Fertility in men and women, as well as menstruation in women, are regulated by a complex interaction of hormones. The ovaries, pituitary gland, and hypothalamus produce these hormones. Follicle-stimulating hormone, or FSH, causes the follicles within the ovaries to mature.

FSH levels may be measured if the healthcare provider suspects a problem with:

menopause, a time in life when menstruation stops

ovarian cysts, which are fluid-filled sacs on the ovary

precocious puberty, or puberty that happens at an abnormally young age

delayed puberty, or puberty that hasn't occurred by the time it should

female infertility, or inability to become pregnant

male infertility, or the inability to impregnate a woman

anovulatory bleeding, which is abnormal vaginal bleeding not related to a regular menstruation cycle

amenorrhea, or the absence of menstruation

testes that are absent or abnormally small

How is the test performed?

A blood sample is taken from a vein on the forearm or hand. First, the skin over the vein is cleaned with an antiseptic. Next, a strong rubber tube, or "tourniquet," is wrapped around the upper arm. This enlarges the veins in the lower arm by restricting blood flow through them. A fine needle is gently inserted into a vein, and the tourniquet is removed. Blood flows from the vein through the needle, and is collected in a syringe or vial. After the needle is withdrawn, the puncture site is covered for a short time to prevent bleeding. The blood sample is sent to the laboratory to determine the amount of FSH circulating in the blood.

What is involved in preparation for the test?

There is generally no preparation for this test. However, the healthcare provider may want to have the test done during a particular time of a woman's menstrual cycle.

What do the test results mean?

Normal values depend upon the sex of the person and other factors. Greater than normal levels of FSH may be found in the following conditions: